1. Assign a gear processing mode of 40ХГР steel with a hardness of 56 ... 58
HRC. Describe the microstructure and properties of the surface of the tooth and the core of the gear after
Heat treatment.
2. Steel P18 was chosen for the manufacture of piercing punches. Specify the composition of steel and
Determine which group to which the steel belongs. Assign and justify the mode
Thermal treatment, explaining the effect of doping on the transformations occurring in ter
Treatment of this steel. Describe the microstructure and properties of the punches after
Heat treatment.
3. For pipes of superheaters, steel 09H14N16B (EI694) is used.
Specify the composition and determine the steel group by by value. Assign a thermal mode
Processing and give its justification. Describe the effect of temperature on mechanical properties
become. Specify the microstructure of the steel after heat treatment.
4. AMg3 alloy was chosen for manufacturing the aircraft parts. Specify the composition of the alloy,
Describe how the alloy is hardened and explain the nature of the hardening.
Specify the characteristics of the mechanical properties of the alloy.
5. Film materials, their varieties, properties and scope in
Machine building.